Abstract
This paper deals with the problem of reproducing different sounds for different areas in the same space. To solve this problem, it is necessary to find a filter that enables the broadband control in the time domain. This paper presents such a solution including following procedures. Firstly, calculate the transfer function from the sound sources to the control points at each target frequency using Fourier transformation. Secondly, find the frequency characteristics of the control filter for each sound source using acoustic contrast control (ACC) based on the transfer function. Then, find the impulse response of the control filter, which can also be seen as the coefficients of a FIR filter, by performing discrete inverse Fourier transformation. Finally, by passing the input signal of a sound source through its corresponding control filter, the sound space can be divided into an acoustic bright zone (area where the input sound can be heard) and a dark zone (area where the input sound can’t be heard). Simulations and experiments are conducted to verify this method, and the results show that the method is effective to deliver different time series signals to different areas. In addition, the reverberate noise that is contained in the control result is also discussed in this paper.
